Diabetes Mellitus: A Major Risk Factor for Cardiovascular DiseaseStatement from Dr. Claude Lenfant, Director, National Heart, Lung, and Blood Institute, and
Dr. Phillip Gorden, Director, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health

The National Heart, Lung, and Blood Institute (NHLBI) and National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) of the National Institutes of Health (NIH) have collaborated with three leading private health organizations on a major public health statement to alert physicians, patients, and the general public to the increasing significance of diabetes mellitus as a major risk factor for cardiovascular disease. In joining this effort, each organization reaffirms its commitment to better understand the causes and unique factors that contribute to excess risk of premature CVD in persons with diabetes, and to develop and implement improved treatments to reduce these complications.

The private organizations that worked with NHLBI and NIDDK on the statement are the American Heart Association, American Diabetes Association, and Juvenile Diabetes Foundation International.

Diabetes mellitus has long been recognized as an independent risk factor for several forms of cardiovascular disease (CVD) in both men and women (e.g., coronary heart disease, stroke, peripheral arterial disease, cardiomyopathy and congestive heart failure). Indeed, cardiovascular complications are now the leading causes of illness and death in the diabetic patient.

Type 2 diabetes, the most common form of the disease, affects approximately 90 percent of the 10.3 million Americans diagnosed with diabetes. An additional 5.4 million persons also are estimated to have type 2 diabetes but remain undiagnosed. Rates of diabetes and milder forms of glucose abnormalities are increasing in the U.S. Above age 65 years, almost half of Americans have abnormal glucose levels.

Type 2 diabetes most often occurs in overweight or obese adults after the age of 30 and typically is preceded by insulin resistance, which also is related to coronary heart disease (CHD). Factors that contribute to insulin resistance and type 2 diabetes are genetics, obesity, physical inactivity, and advancing age, all of which are also the major predisposing risk factors for cardiovascular disease.

The increasing prevalence of type 2 diabetes is related to a variety of factors, many of which also are associated with an increased risk of CVD. These factors include: the rising prevalence of obesity in the United States (an estimated 97 million American adults are overweight or obese); the relatively low levels of physical activity among American adults (approximately 25 percent of adult Americans engage in regular physical activity of any intensity); increasing age of the population; the rapid growth in the United States of populations that are particularly susceptible to type 2 diabetes - African Americans, Hispanics. Native Americans, Pacific Islanders, and Asians; and improved medical care which prolongs life, thus increasing the risk for development of type 2 diabetes and its CVD complications.

NHLBI and NIDDK emphasize that both CVD and type 2 diabetes may be prevented or at least postponed by lifestyle changes that maintain normal weight and physical activity. Thus, modification of life habits is at the heart of the public health strategy for reducing rates of type 2 diabetes and its cardiovascular complications.

Drug therapy may be required to control diabetes and CVD risk factors, especially when diet and exercise are not sufficient. Highly effective medications are now available to control high levels of blood sugar, blood pressure and cholesterol. In recent years, several new drugs have been introduced that can lead to greatly improved control of diabetes and CVD risk factors. Unfortunately, many patients with type 2 diabetes still have high levels of these risk factors and efforts are necessary to get health providers and patients to improve risk factor control.

Much of what we know about the cardiovascular complications of diabetes - and how they can be prevented or treated - has come from studies supported by NHLBI and NIDDK. In fact, in recent years these NIH institutes have substantially increased research in this area.

This year, NHLBI and NIDDK will start two large clinical trials designed to identify ways to reduce cardiovascular complications of type 2 diabetes. The Prevention of Cardiovascular Disease in Diabetes (PCDD) trial will study the benefits of intensified control of high blood sugar, cholesterol and hypertension. The Study of Health Outcomes of Weight Loss (SHOW) trial will focus on the benefits of weight loss in obese individuals with diabetes. Together, they will provide important information about the effectiveness of several new medications and treatment regimens to reduce the complications of diabetes. Until ways to prevent or cure diabetes are found, such trials offer the best opportunity to reduce the burden of diabetes.

Surveys show that physicians often are not emphasizing approaches to reduce the risk of cardiovascular disease in their patients with diabetes. For this reason, NHLBI, NIDDK, and the collaborating organizations named above pledge to work together to educate health professionals and the public about diabetes as a major CVD risk factor.

Working with our partner organizations, NHLBI and NIDDK are also committed to initiating future collaborative research and programs to ensure that the results benefit patients through improved clinical management and prevention.

For more information on heart disease and risk factors for cardiovascular disease, visit the NHLBI Web site at http://www.nhlbi.nih.gov.